Theoretical and hands-on guidance from dental hygienists promotes good oral health in elderly people living in nursing homes, a pilot study.

OBJECTIVES: Oral health in nursing homes for elderly is often unsatisfactory, and oral health education to nursing staff has not shown sufficient results why there is need for novel approaches. The aim of the study was to trial a new oral healthcare educational programme and to evaluate the effects on residents' oral health. In addition, attitudes among the nursing staff in the intervention nursing home were explored. METHODS: In a controlled clinical trial, two comparable nursing homes were randomly assigned for intervention or control. Interventions included weekly theoretical and hands-on guidance from dental hygienists on oral hygiene procedures and discussions on oral care routines. The residents' oral health, measured by the Revised Oral Assessment Guide (ROAG), dental plaque and gingival bleeding were evaluated at baseline and after 3 months. Attitudes among the staff to oral health care were measured at the intervention nursing home. RESULTS: Revised Oral Assessment Guide gums and lips scores showed a tendency to decrease in the intervention group, but remained high in the control group. Plaque levels improved significantly after intervention, and a trend towards less gingival bleeding was observed. The intervention nursing staff seemed to be more aware of their own limitations concerning oral health care after intervention and valued more frequent contact with dental services to a greater extent. CONCLUSIONS: The oral healthcare situation for elderly people today is so complex that theoretical education at the group level regarding different aspects of oral health is not sufficient. Individual hands-on guidance by dental hygienists on a regular basis in everyday care may be a new approach.

Oral care perspectives of professionals in nursing homes for the elderly.

OBJECTIVES: Good oral health is an important aspect of quality of life. However, a number of studies have shown that oral care for the dependent elderly is unsatisfactory. The aim was to explore in nursing homes for the elderly what professionals with different responsibilities may consider as being important aspects of well-functioning daily oral care. METHODS: A total of 23 informants from three municipalities in the region of Värmland, Sweden, were interviewed. An interview guide was used, containing some demographic and open-ended questions about individual perceptions of issues according to the study aim. The interviews were tape-recorded and transcribed verbatim. RESULTS: In the manifest and latent analyses, six categories and three themes emerged. The categories were Key Processes, Communication, Priorities, Competence, Good Oral Health and Autonomy. The themes were Organization, Staff Approach and Staff's Views on Residents' Needs. An overall picture emerged that oral care, rather than occupying an integral position, played a peripheral role in nursing care. CONCLUSIONS: To improve oral care, there are opportunities to work with existing structures and clarify responsibilities and key processes. Oral care should be included in nursing work as a more highly prioritized task, and nurses' knowledge needs to be enhanced. A network of activities at all levels is needed to implement oral care in nursing care.

Porphyrin triplet state probing the diffusion of oxygen in hemoglobin.

Laser photolysis study of porphyrin-globin shows that the triplet state of the porphyrin is detectable by its light absorption and that it can be used to determine the rate of penetration of oxygen into the hemoglobin pocket in which the porphyrin is embedded. The oxygen penetration rate does not determine the binding rate of oxygen to iron in hemoglobin.

Genetic control of susceptibility to pulmonary infection with Chlamydia pneumoniae in the mouse.

A mouse model was used to study the genetic control of differential host response to pulmonary infection with Chlamydia pneumoniae. The A/J and C57BL/6 strains show differential response to intranasal infection with respect to their ability to clear pulmonary bacterial load and the extent of lung pathology developed by 2 weeks post infection. The genetic basis of this interstrain difference was studied by whole-genome scan in an informative [A/J x C57BL/6J] F2 cross using the pulmonary microbial load as a phenotypic readout of host response. We detected a highly significant linkage (LOD score=11.5) on chromosome 17 that overlaps with the major histocompatibility (MHC) locus. This quantitative trait locus (QTL) accounts for approximately 30% of the phenotypic variance with B6 alleles conferring susceptibility and inherited in a recessive fashion. Significant linkage was also detected to chromosome 5 in female mice, while chromosome 6 showed suggestive linkage in male mice, pointing to additional complexity in the genetic control of the difference in susceptibility observed in A/J and C57BL/6J.

Cell death is not essential for caspase-1-mediated interleukin-1ß activation and secretion.

Caspase-1 cleaves and activates the pro-inflammatory cytokine interleukin-1 beta (IL-1ß), yet the mechanism of IL-1ß release and its dependence on cell death remains controversial. To address this issue, we generated a novel inflammasome independent system in which we directly activate caspase-1 by dimerization. In this system, caspase-1 dimerization induced the cleavage and secretion of IL-1ß, which did not require processing of caspase-1 into its p20 and p10 subunits. Moreover, direct caspase-1 dimerization allowed caspase-1 activation of IL-1ß to be separated from cell death. Specifically, we demonstrate at the single cell level that IL-1ß can be released from live, metabolically active, cells following caspase-1 activation. In addition, we show that dimerized or endogenous caspase-8 can also directly cleave IL-1ß into its biologically active form, in the absence of canonical inflammasome components. Therefore, cell death is not obligatory for the robust secretion of bioactive IL-1ß.

One-electron photo-oxidation of reduced Desulfovibrio vulgaris flavodoxin on laser excitation at 355 nm.

Electron ejection from the reduced flavin in flavodoxin from Desulfovibrio vulgaris was obtained on exposure of the protein to the third harmonic radiation (354.7 nm) generated from a pulsed Nd/YAG laser. The results indicate that the reaction is due to stepwise two-photon excitation of the reduced flavin via the excited singlet state. The absorption spectrum of the neutral flavosemiquinone radical formed in this process was obtained. This spectrum remains stable over the time of study (0.2 ms) in the pH range studied, except for a slight evolution during the first microseconds, attributed to conformational readjustments of the active site. This two-photon excitation method provides a convenient means of generating the flavosemiquinone for ultrafast kinetic studies.

Quantitative changes in aminoacylation of transfer RNA and in free amino acids during fructose-induced depletion of adenine nucleotides in rat liver.

Fructose induces depletion of adenine nucleotides in liver and also strongly inhibits incorporation of radioactive amino acids into protein (Mäenpää, P.H., Raivio, K.O. and Kekomäki, M.P. (1968) Science 161, 1253-1254). In this study we have investigated the effects of fructose on aminoacylation of tRNA and on free amino acids in rat liver. 30 min after D-fructose (30 mmol/kg) was injected intraperitoneally into rats, liver ATP was reduced by 58%, ADP by 42%, AMP by 13%, the ATP/ADP ratio by 30%, and total adenine nucleotides by 48%. Using gas chromatography, the aminoacylation of tRNA was determined by quantifying the endogenous amino acids attached to tRNA in vivo. Aminoacylation was reduced by 31%. With different amino acids, reduction varied from 4% (asparagine plus aspartic acid) to 58% (arginine). On the other hand, the amount of free amino acids in the liver was increased by 24%. The most marked individual change was in alanine, which increased 5.7-times. This may have resulted from a combination of effects involving an increased production of alanine in muscle and liver and decreased hepatic gluconeogenesis from alanine caused by the ATP depletion.

Current questions and possible controversies in autophagy.

Interest in autophagy has exploded over the last decade, with publications highlighting crosstalk with several other cellular processes including secretion, endocytosis, and cell suicide pathways including apoptosis. Autophagy proteins have also been implicated in other cellular processes independently of their roles in autophagy, creating complexities in the interpretation of autophagy (Atg) mutant gene data. Interestingly, this self-eating process is a survival mechanism that can also promote cell death, but when and how autophagy may 'switch' its function is still under debate. Indeed, there are currently many models of how autophagy actually influences cell death. In this review, we highlight some outstanding questions and possible controversies in the autophagy field.

Effects of buffer salt on the geminate recombination of photodissociated carboxyhemoglobin and its isolated subunits.

The geminate recombination of photodissociated carboxyhemoglobin (human adult) and its isolated subunits was studied by nanosecond laser photolysis. The rebinding kinetics were found not to depend upon the kind of buffer used or on pH but changed appreciably with the buffer concentration. The results are compared to oxygenation properties under the same conditions.

Metabolic responses to exercise in the racehorse: changes in plasma alanine concentration.

Previous studies in humans have shown that alanine is released from the skeletal muscle in proportion to the work load. We have measured plasma alanine and urea concentrations in well-trained Standardbred and Finnish-bred (cold-blooded) trotters after a graded-intensity exercise and during recovery to study metabolic responses to exercise in this animal model. As controls we measured blood lactate, pyruvate, and glucose concentrations as well as hematocrit values. Metabolic responses to exercise were closely reflected in all these parameters. Plasma alanine increased relatively more than plasma lactate at moderate-intensity exercise near anaerobic threshold. The linear correlation between the intensity of exercise and plasma alanine was similar to that observed earlier in humans. Interestingly, plasma alanine concentrations remained elevated long after the submaximal exercise, whereas the concentration of lactate, pyruvate, and glucose decreased more rapidly. No significant changes were found in plasma urea concentration under these conditions. The most significant differences in the metabolic responses to exercise of the two breeds studied were the higher lactate-to-pyruvate ratios achieved during the high-intensity exercise and the more sensitive increases of plasma alanine even during low-intensity exercise in the Finnish-bred horses. These differences probably reflect different compositions of muscle fiber types in the two breeds. The findings together indicate that plasma alanine is greatly increased in the racehorse during and after a high-intensity exercise and thus is an important vehicle in transporting ammonia and carbon skeletons of products of anaerobic glycolysis out of the muscle tissue.

Excited-state dynamics of fully reduced flavins and flavoenzymes studied at subpicosecond time resolution.

The photophysics of the fully reduced states of a number of flavins (flavin mononucleotide, flavin adenine dinucleotide and 3-N-methyllumiflavin) and flavoenzymes (glucose oxidase from Aspergillus niger and the flavodehydrogenase component isolated from flavocytochrome b2) was studied using subpicosecond laser excitation at lambda = 312 nm. The prompt transient absorption spectra (measured from 400 to 850 nm) were all closely similar in the case of the free flavins in aqueous solution. The decay of the transient absorbance obeyed biexponential kinetics with a fast component of lifetime ranging from 4 to 130 ps and a slower phase with a lifetime above 1 ns. The spectral structure changed appreciably during the rapid decay phase. In contrast, in the case of the enzymes only a very slight decay was apparent over the probed time interval (1 ns) and the shape of the spectrum remained unchanged. It is proposed that the two transient spectra appearing in the free flavins correspond to two conformations differing by their degree of nonplanarity, whereas in the flavoenzymes only one conformation is possible.

Determination of the absolute configuration of sugar residues using gas chromatography. Method with potential for elimination of references.

The absolute configuration of a sugar can be determined by gas-liquid chromatography of the acetylated or trimethylsilylated dithioacetals from 1-phenylethanethiol. The isolation of both enantiomers of 1-phenylethanethiol is also described. Using the acetates and both thiol reagents the absolute configuration of C-2 can be determined, provided it is a hydroxyl group, with great certainty. A new way of determining the absolute configuration of sugars, without references, is thereby provided. The sugars analysed include aldoses, deoxyaldoses, 2-acetamido-2-deoxyaldoses and uronic acids. The analysis is made using columns with non-chiral stationary phase and the electron impact mass spectra of the acetylated and trimethylsilylated bis(1-phenylethyl)dithioacetals are described.

Reaction mechanism in the photochemistry of the antileukaemic agents 2-chloro- and 2-bromo-2'-deoxyadenosine, studied by nanosecond laser flash photolysis.

The reaction mechanism in the UV photochemistry of 2-chloro-2'-deoxyadenosine (Cladibrine) and 2-bromo-2'-deoxyadenosine in aqueous solution has been studied by laser photolysis at nanosecond time resolution. It is found that excitation at 266 nm wavelength produces heterolytic cleavage of the halogen-carbon bond by one-photon absorption and formation of the unstable 2-hydroxy tautomer of 2'-deoxyisoguanosine as predominant 'primary' product. The 2-hydroxy tautomer then transforms in 10(-6)-10(-5) s into the stable 2-oxo tautomer in an acid-base-catalysed reaction. A reaction mechanism is proposed and discussed in relation to previous UV low-intensity studies of these halogenodeoxyadenosines.

Influence of the gel-liquid phase transition on hematoporphyrin triplet deactivation in liposomes.

The deactivation of the triplet state of hematoporphyrin and its dimethyl ester in unilamellar liposomes of dipalmitoyl phosphatidylcholine was studied by nanosecond laser flash photolysis. It was found that the rate of deactivation increases abruptly on raising the temperature in the region of the gel-liquid phase transition of the lipid bilayer (41 degrees C). The rate of change has its maximum at 38.4 +/- 0.5 degree C for both porphyrins. This variation is due to the high lateral mobility of the porphyrins in the liquid-crystal bilayer, which enhances the rates of concentration triplet quenching and triplet-triplet annihilation.

Quenching of merocyanine 540 triplet state by nitroxyl radicals in liposomal systems: a laser flash photolysis study.

Laser flash photolysis experiments were undertaken to investigate the interaction between stearic acid nitroxide spin probes and photoexcited merocyanine 540 (MC540) in dimyristoyl-L-alpha-phosphatidylcholine liposomes (membrane model). The measurements of the paramagnetic signal decay kinetics of four different spin-labelled stearic acids (n-DSA) show that the direct interaction between the dye and the probe is affected by the position of the nitroxyl group along the carbon chain. Laser flash photolysis results reveal a significant decrease in the MC540 triplet lifetime in the presence of n-DSA, the effect depending on the depth at which the nitroxyl moiety is localized in the bilayer. Previous results on the rate of disappearance of the electron spin resonance (ESR) nitroxide signal on continuous photolysis of the same systems do not show the same dependence on the localization of the nitroxyl moiety in the liposome. Although the MC540 triplet state seems to be implicated in the reaction process, the results suggest that ESR and laser flash experiments demonstrate two different kinds of mechanism.

Intermediates in the oxidation of a dihydropyridine derivative of AZT related to AIDS dementia, studied by nanosecond laser photolysis.

Radicals of the AZT derivative 5'-(1,4-dihydro-1-methyl-3-pyridinylcarbonyl)-3'-azido-2',3'-dideo xythymidine) were obtained on exposure of this compound in alkaline aqueous solution to pulsed laser emission of lambda = 355 nm and pulsewidth 2 ns FWHM. The radical formation was shown to be due to photoelectron ejection from the pyridine group following two-step excitation of the compound. The radicals were found to deprotonate rapidly. Electrochemical analysis showed that the photoionization does not affect the azido group.

Cadmium and zinc in Mytilus edulis L. from the Bothnian Sea and the northern Baltic proper.

Contents of Cd and Zn in the blue mussel, Mytilus edulis, collected on the coast of the southern Bothnian Sea and the northern Baltic proper, were determined using flame AAS. The observed concentrations ranged from 4.7 to 10.8 mg kg(-1) dw for Cd and from 121 to 215 mg kg(-1) dw for Zn. The Zn/Cd ratio was around 20 at a majority of the investigated locations. Cd exhibited an approximate two-fold gradual increase from south to north in the study area. It is likely that this increase was due largely to enhanced bioavailability for Cd at lower salinity. However, it is not possible to eliminate the influence from a generally elevated overall concentration of cadmium in the southern Bothnian Sea caused by natural and anthropogenic input. Compared to mussels from marine waters on the west coast of Sweden, Cd concentrations were 5-10 times higher, similarity indicating an influence of low salinity. Zn did not show these salinity correlated differences. The high Zn content found south of the outlet of the river Dalälven and gradually decreasing southwards was possibly caused by the high riverine input.

Masticatory movements in patients treated with fixed prosthesis on osseointegrated dental implants in the mandible.

Mandibular movements were recorded by means of an optoelectronic system (Sel spot) in 16 complete denture wearers before and after insertion of tissue integrated prostheses in the mandible. Analysis of the single chewing cycle revealed an obvious increase in mandibular velocity and displacement after rehabilitation. The duration of the occlusion phase was also significantly shortened, probably due to the stabilization of the occlusion provided by the fixed implant bridge.

Effect of inactivated salivary lysozyme on L(+)-lactic acid production in saliva and in cultures of Streptococcus mutans BHT.

The aim of this study was to evaluate the antimicrobial contribution of human lysozyme in saliva. In one series of experiments, L(+)-lactic acid (LA) production in exponential phase cultures of Streptococcus mutans BHT treated with lysozyme-deficient salivary supernatant was determined. In other experiments, LA concentration was measured in whole saliva samples from 22 school-children where the lysozyme activity had been inhibited by the addition of goat antiserum to human lysozyme (GAsL). LA production in both S. mutants cultures and saliva samples was stimulated by D-glucose addition. The results indicated a time dependent increase (approximately 30%) in LA production in lysozyme-deficient reaction-mixtures compared to untreated controls. The mean LA concentration in lysozyme-inactivated whole saliva samples was significantly higher (p less than 0.01) compared to untreated saliva. However, in 4 out of 22 children the GAsL-treatment did not affect LA production. The individual differences could not be related to salivary secretion rate, lysozyme activity or the number of S. mutans and lactobacilli in saliva. The findings of this study suggest a protective role for lysozyme in limiting acid production in saliva, but individual differences exist.